Roman Cheplyaka <roma at ro-che.info> writes:
> But there's another problem... The "right" instance should really be
> based on Semigroup, not Monoid, but Semigroup is not currently in the
> base. And adding a dependency on semigroups to containers is hardly an
> option.
just to be clear, do you propose the instance to read
instance (Ord k, Semigroup v) => Monoid (Map k v)
or rather
instance (Ord k, Semigroup v) => Semigroup (Map k v)
?
cheers,
hvr